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Y (No Model.) 3 Sheets-Sheet 1.

F. W. SPACKE.

GAS ENGINE.

10.593,034. Patented Nov. 2,1897.

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No. 593,034. Patented N0V..2, 1897.

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(No Model.) 3 sheets-*sheet 3. F. W.SPAGKB.

GAS ENGINE Patented Nov. 2,1897.

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WVM/mwa@ 'mz Norms Psrms co, muro-nwo wAsHmmoN, u c4 arent* errent FRED W. SPACKE, OF INDIANAPOLIS, INDIANA.

GAS-ENGlNE.

SPECIFICATION kforming part of Letters Patent No. 593,034, dated November 2, 1897.

Application filed April 7, 1896. Serial No. 586,572. (No model.)

.'o @ZZ whom t may concern:

Be it known that I, FRED W. SPACKE, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful GasEngine, of which the following is aspecification.

My invention relates to an improvement in gas-engines.

The objects of my invention are, first, to produce a double-acting gas-engine; second,` to provide means for heating the air before it is mixed with the gas; third, to provide improved means for exploding the gas, and, foulth, to provide improved means for removing the exhaust from both ends of the cylinder.

The accompanying drawings illustrate my invention.

Figure 1 is a side elevation of the cylinder end of my improved engine. Fig. 2 is a central vertical section thereof. Fig. 3 is a central horizontal section thereof. Fig. 4 is a transverse section on line 4 4 of Fig. 3. Fig. 5 is a central vertical section of the gas-inlet valve. Fig. G is a central horizontal section thereof. Fig. 7 is a side elevation of the gas-inlet-valve-operating mechanism. Fig. 8 is a detail. Fig. 9 is a detail. Fig. 10 is a plan of means for regulating the supply of air, and Fig. 11 is a side elevation thereof.

In the drawings, 12 lindicates a cylinder of uniform bore and provided with the usual water-jacket 13. The rear end of cylinder 12 is closed by a cap 14, which consists of a hollow central cylindrical portion l5, having a closed inner end 16 and an outturned flange 17, formed on the outer end of said cylindrical portion. Part 15 extends a short distance into the cylinder and fits therein, and the inner surface of flange 17 is ground perfectly true and fits against and forms a perfect joint with the trued and ground end of the cylinder. Cap14 is held in position by means of a series of bolts 18, which pass through flange 17 and into the end of the cylinder. In case the end of the cylinder were closed by a substantially flat plate the extreme heat caused by the explosion of the gas would cause the said plate to buckle in the center and thereby have a tendency to openthe joint between the plate and the end of the cylinder. As a consequence it is necessary to insert'some kind of packing between the said plate and cylinder.-

In the construction described above the inner end 16 of the cylindrical portion 15 is the only portion of the cap which is subjected to the extreme heat of the interior of the cylinder, and this portion of the cap may expand and contract without in any degree affecting the joint between iiange 17 and the end of the cylinder. It is therefore possible to form a ground joint between said parts and to keep said joint perfectly tight.

A piston 19 is mounted in cylinder 12, and piston-rod 2O is secured to said piston by means of nuts 21 and 22, and said piston-rod is also connected to a suitable crank-shaft carrying a fly-wheel in the usual manner.

Piston 19 is made considerably longer than its stroke, and each end of said piston is provided with suitable packing-rings 23, which are sprung into place in the usual manner. The middle portion of the piston is made con siderably smaller in diameter than the ends thereof for a dist-ance slightly greater than the stroke, so as to form an air-chamber 24 between the middle portion of the piston and the cylinder.

The forward end of the cylinder is closed by a cap 25, having a hollow cylindrical portion 26, which has a closed inner end 27. The inner end of cap 25 projects into and fits cylinder 12, and extending from about the middle of the outer periphery of portion 26 is a fiange 28, the inner surface of which is trued and ground and forms a perfect joint with the trued and ground end of the cylinder by means of a series of bolts 30, passing through the flange and into the end of the cylinder. Formed integral with end 27 and projecting outward therefrom is a central hollow boss 31, through which the piston-rod is adapted to pass. The outer end of boss 31 is provided with a suitable stuffing-box 32, and the outer end of said stuffing -box lies substantially flush with the outer end of portion 26, the annular opening between the stufng-box and the cylindrical portion being closed by means of an annular plate 33, which is secured to the end of said cylindrical portion by means of bolts 34. I/Vater-jacket 13 extends a short distance beyond the inner ends of caps 14 and 25, but does not extend the entire length of the cylinder. For the purpose of establish- IOO ing connection between said jacket and the interior of cap 25 a series of holes 35 is bored through flange 2S into the interior of cap 25, and a series of holes 36, communicating with holes 35, is bored through the end of the cylinder into the water-jacket. By this construction a water-jacket is provided for the bearing of the piston-rod and for the stufngbox thereof, thus preventing the stuffing from being burned out.

Opening into the bottom of cylinder 12, about midway thereof, is an air-inlet 37, said inlet communicating with the air-chamber 24, which surrounds the middle portion of piston 19,and leading from said air-chamber through the side of the cylinder is an air-outlet 3S, which leads into a mixing-chamber 39, formed in an open-ended casing 40, which is bolted to the side of the cylinder over the said aire outlet. The open ends of the casing are closed by valve-boxes 41 and 42, which are bolted to the side of the cylinder over the mouth of ports 43 and 44, respectively, which open into the cylinder near the opposite ends thereof. Valve-box 41 is provided with a central partition 45, which is substantially parallel with the axis of the cylinder, and between said partition and the outer wall of the box is a partition 46, the arrangement being such that the interior of said box is divided into' three chambers 47, 48, and 49, said lastmentioned chamber extending entirely across the box and communicating with port 43. Box 42 is similarly divided by partitions 50 and 51 into chambers 52, 53, and 54, chamber 54 extending entirely across the box and communicating with port 44. Partition 45 of box 41 is provided with a pair of openings 55 and 56, said openings forming a communication between chamber 49 and chambers 47 and 48, respectively, and partition 50 of box 42 is provided with a similar pair of openings 57 and 5S, said openings forming a communication between chamber 54 and chambers 52 and 53, respectively. An opening 59 leads from mixing-chamber39 into chamber 53,and a similar opening 60 leads from said chamber 39 into chamber 48.

Mounted in suitable bearings in box 41 is an admission-valve 62 and an exhaust-valve 61, the arrangement being such that when the valve-stems thereof are moved outward valve 6l will close opening 55 and valve 62 will close opening 56. Box 42 is similarly provided with admission-valve 63 and exhaust-valve 64. Pivoted to box 41 below the Valve-stems are two levers 65 and 66, the u pper ends of said levers being bifurcated and adapted to engage an I-shaped head 67, secured to the outer end of each of said valvestems. A spring 68 is secured at one end to the lower portion of each lever and at the other end is secured to box 41, so that the normal position of each lever will be such as to hold shut the valve operated thereby.

Mounted in suitable bearings on the engine-frame is a shaft 69, the forward end of the corresponding valve.

which is connected with the crank-shaft of the engine by suitable gearing to cause said shaft to rotate at one-half of the speed of the said crank-shaft. Secured to shaft 69 opposite the lower ends of levers 65 and 66, respectively, are two cams 70 and 7l, the said cams being so situated as to force the lower ends of their corresponding levers outward when the shaft is rotated and thereby open The lower end of each lever is so shaped and placed in relation to the operating-cam that the lower end of said lever will be thrown outward by said cam whether the said cam is rotated in the direction indicated by the arrow or in the opposite direction.4 Pivoted to box 42 below the stems of valves 63 and 64 are a pair of levers 72 and 73, the said levers being similar to levers 65 and 66, and the upper end of each of said levers engaging an I-shaped head 67, secured to the outer ends of the stems of valves 63 and 64. Secured to shaft 69 in position to engage with the lower ends of levers 72 and 73, respectively, are two cams 74 and 75, said cams being similar in construction and operation to cams 70 and 71.

Chamber 39 is somewhat enlarged at each end opposite openings 59 and 60, and leading from each of said enlarged portions is a passage 76, which opens into a gas-supply pipe 77. The opening between pipe 77 and passage 76 may be regulated by means of a plug 7S, which is screwed into the outer end of passage 76 and is adapted to be moved across the lower end of pipe 77 and held in any of its adjusted positions by means of a checknut 79. In the inner end of passage 76 is secured a valve-carriage S0, from the inner end of which project a pair of arms 81, which carry about midway of their length a short cylindrical guide S2 and the ends of which are connected by means of a cross-bar 83. Mounted so as to close the opening in valvecarriage SO is a valve S4. valve 84 is adapted to slide through an opening formed in cross-bar 83, and said stem is providedwith a collar 85', which is adapted to fit and to slide in guide 82, and a spring S6, mounted between said collar and crossbar, tends to keep said valve closed. Secured to collar 35 and passing through a slot 87, formed in guide S2, is a pin 8S. Pivot-ed to pin 38 is a lever S9, the outer end of which extends through a slot 90,' formed in casing 40. The outer end of said lever is provided at its upper and lower sides with a short spur 91, and said outer end is adapted to be engaged by the notched end 92 of a pin 93, one of which is secured to each of the heads 67, carried by each of the admission-valves 62 and 63. The inner end of lever 89 is adapted to be engaged by an arm 94, carried by a rock-shaft 95, the said inner end of the lever remaining in contact with the arm owing to the greater weight of the outer end of the lever.

Mounted in suitable bearings on casing 40 I IOO IIO

The stem S5 of is a governor 96, adapted to operate an arm 97, secured to shaft 95, and to'thereby operate arm 94. To the lower end of the governorshaft is secured a gear 98, which meshes with a gear 99, secured to shaft 69. The particular construction of this governor has been described and claimed in application Serial No. 586,570, filed herewith. I

For the purpose of exploding the gas in the cylinder I provide the following mechanism: A sleeve 100 leads into each end of the cylinder at the top thereof, said sleeve being provided at its upper end with a flan ge 101, which engages the outer surface of the cylinder. Mounted one on each side of sleeve 100 are two bolts 102, over which is slipped a bar 103, which is provided with a downwardly-extending boss 104, which is adapted to lit into the upper end of sleeve 100. Bar 103 is provided with a central opening in which is mounted an annular insulatin g-packin g 105. Mounted in said packing and extending therethrough is a metallic bolt 106, which is provided at its lower end with a head 107 and at its upper end with suitable screw-threads to receive a nut 108. A suitable insulating-washer 109 is placed between head 107 and boss 104 and a similar washerllO is placed between nut 108 and bar 103. `The lower end of bolt 106 is slotted to receive a downwardly-extending spring 111, which is secured therein by any suitable means and is provided near its lower end with a contact-piece 112, preferably platinum. A wire 113 is secured to the upper end of bolt 106 and from there passes to one pole of any suitable battery.

The ends of piston 19 are preferably made hollow, so as to form chamber 114 therein, and the said ends are each partially closed by a plate 115, each of said plates being provided with a central opening 116, which forms a communication between chamber 114 and the interior of the cylinder. The use of said plates will be fully set forth in the description of the operation. Secured to each of said plates are a pair of parallel guides 117, the adjacent edges of said guides being beveled, as at 118. Fitted between said guides is a longitudinally-movable nut 119, provided with a head which lits between the beveled edges of the guides, and also provided with a pair of flanges adapted to engage the lower surfaces of guides 117, the arrangement being such that the said nut cannot fall through between the guides. Nut 119 is adapted to receive the lower screw-threaded end of a standard 120, provided about midway of its length with a collar 121, the lower end of which is adapted to engage the upper surfaces of guides 117 andA said standard is provided near its upper end with a contact-piece, preferably platinum, 122, which is adapted to engage with contact-piece 112 of spring 111. Secured to gear 99 and projecting from the rear face substantially parallel to the axis thereof are two contact-pins 123 and 124, pin

123 being set substantially ninety degrees in advance of the other pin.

Secured to the side of the engine-bed is a block 125, formed of porcelain or other suitable insulating material, and secured to said block and projecting therefrom is a iiat metallic plate 126, provided near its outer end with a suitable contact-piece, (shown in dotted lines in Fig. 8,) the arrangement being such that pins 123 and 124 will be successively brought into contact with the contact-piece on plate 126 by a rotation of shaft 69. A wire V127 leads from plate 126 to the pole of the battery opposite the one to which the wires 113 are attached. In order to prevent a leakage of gas through slot 90 of casing 40, the ends of said casing are preferably rounded, as at 128, and mounted thereon over slot 90 is a slide 129, which is provided with a small opening through which lever 89 may pass. Slide 129 is kept in position over slot 90 by means of a pair of guides 130, which are secured to casing 40 and project over said slide.

It is often desirable to be able to regulate the amount of air which is introduced into mixing-chamber 39, and for this purpose I mount in a slot 141, (shown in dotted lines in Fig. 11,) formed in casing 40, aslide-valve or plate 142, the lower end of said plate engaging in a recess formed in the interior of the lower side of casing 40. Plate 142 has formed integral therewith a guard 144, which is bent substantially at right angles to said plate and extends to each side thereof, so as to form a covering for slot 141 in whatever position plate 142 is placed in slot 141. Guard 144 has formed therethrough a slot 145, through which is passed a thumb-screw 146, by means of which plate 142 may be secured in any position across air-outlet 38. A suitable pointer 147 is carried bythe guard and is adapted to indicate the position of plate 142 by means of a suitable scale carried bythe upper surface of casing 40.

For the purpose of lubricating piston 19 an oil-cup 148 is mounted on top of the cylinder about midway of its length and is connected with the interior of the cylinder by means of a passage 149. Secured to piston 19 and reaching from end to end of the hollowed-out portion thereof is a narrow oil-bridge 150, provided in its upper surface with a shallow groove 151. As the piston moves back and forth the oil drops into groove 151 and is thrown back and forth in said groove and thus reaches the ends of the piston.

Opening into chamber 52 is an exhaustpipe 152, and opening into chamber 47 is a similar pipe 153. Pipe 152 is connected to a coupling 154, which leads directly into an exhaust-drum 155, while pipe 153 is connected to coupling 154 by means of a branch 156, which leads into said coupling at an acute angle, so that the exhaust-gases which pass through pipe 153 are led into the coupling at such an angle that the passage of the gases IOO will tend te create a suction in pipe 152, and the passage of the gases through pipe 152 will also tend to produce a suction in pipe 153. By this construction the exhaust from one end of the cylinder does not tend to retard the exhaust from the other end of the cylinder, but, on the contrary, the exhaust from each tends te force the exhaust from the other into the drum.

The piston-rod as it travels back and forth through stuffing-box 32 's covered with oil, and a portion of this oil is carried inte the cylinder and would there be charred by the burning gases. To prevent this, 1 secure to the inner end of cap 25 a hollow shield 157, which surrounds the piston-rod and extends inte the cylinder a distance slightly greater than the stroke. Shield 157 does net touch the piston-red, but lies very close thereto, so tha the ilames from the burning gases cannet come into contact with the eil on the piston-red.

rlhe operation of my device is as follows: Supposing water-jacket 13 to be connected with any suitable supply of water, pipes 77 te be connected with any suitable supply of gas, a supply of mixed gas intred need through opening (50, chamber 4S, opening 5G, chamber 49, and port 43 into the rear end of the cylinder, and a similar supply of mixed gasintroduced through opening 59, chamber53, opening 58, chamber 5-1, and port -1--12 inte the forward end of the cylinder. lVith the parts in the position shown valves 61 and (32 are closed, the gas in the rear end ef the cylinder has been compressed, contact-piece 122 is in engagement with contact-piece 112, and pin 123 is in engagement with plate 12 6. An electric circuit is therefore completed from the battery through wire 127, plate 126, pin 123, gear 99, shaft G9, through the entire engine-bed, cylinder 12, piston 19, plate 115, guides 117, standard 120, contacts 122 and 112, spring 111, bolt 10G, and wire 113 to the battery, bolt 10G and spring 111 being entirely insulated from the cylinder by means of packing 105 and washers 101- and 110. The operator pulls piston 19 forward, and as contacts 122 and 112 are separated a spark is caused, which i gnites the gas and causes an explosion thereof. The expansive force of the exploded gas causes piston 19 to move forward, at the same time compressing the gas in the forward end of the cylinder. lVhen the piston reaches the forward end of its stroke, it is caused te move backward therein by the momentum of the crank-shaft and the usual fly-wheel carried thereby. 11s the said piston moves backward contacts 122 and 112, at the forward end of y the cylinder, are separated, and a spark is formed which causes an explosion of the gas in the forward end. The movement of the piston has caused a rotation of the crankshaft in the usual manner and the rotation of said crank-shaft has caused shaft G9 to rotate in the direction indicated by the arrow, the said shaft moving through an angle of ninety degrees while the piston moves through the `length of the cylinder.

The movement oi' shaft G9 has thrown pin out of engagement with plate 126 and has brought pin 12st into engagement therewith, said pin 121 coming into engagement with the plate at the same time that contacts 122 and 112 come into engagement, and remaining in engagement with said plate until after said contacts have been separated. As the piston begins to move backward cam is brought into engagement with the lower end of lever 65 and the said lower end is forced outwardagainst the action of spring 63, the upper bifurcated end of said lever being forced inward, and thereby, by means of headb7, forcing exhaust-valve Gl open. The continued rearward movement of the piston causes the exploded gases to be forced out through port into chamber 19, from there through opening 55 into chamber 47, and from there out through pipe 153, through coupling 15-1, and inte drum 155, from which it passes te the outer air. rihe piston has in the operation become heated and the cold outer air which enters inlet 37 has passed into chamber 21 and has become heated by contact with said piston. From chamber 21 the heatedairpassesinto chamber3 l'v'hen the piston again reaches the rear end of the cylinder, contacts 122 and 112 again come into engagement, but they do not complete a circuit through the battery, owing te the fact that both pins 123 and 121 are eut ofengagement with plate 126. As the piston again moves forward cam '70 leaves lever U5 and valve (il is closed by its spring G3. At the same time cam 71 comes inte contact with lever 6G and thereby opens admission-valve G2, and also cam 75 comes into contact with lever 7 3 and thereby7 opens exhaust-valve (il. At the same time the advance of head G7 en valve G2 brings the notched end 92 of pin 93 into engagement with the outer end of lever S9 and forces said lever inward,thereby opening valve 81 against the action of spring 3f). The gas passes from pipe 77 through passage 7G and into chamber 39, where it becomes mixed with the heated air which is in said chamber. The advance of the piston causes a suction which draws the mixed air and gas through opening G0, chamber 13, opening 5G, chamber 119, and port into the rear end of the cylinder, the said advance causing the exploded gases in the forward end of the cylinder to pass out through port lill, chamber 5-i, opening 57, chamber 52, pipe 152, coupling 15a, and drum 155. Afterexhaust-valve (51 has been closed there still remains in the rear end of the cylinder and in chamber 111 of Athe rear end of the piston a quantity of exploded or dead` By the introduction of plate 115 the dead gas in chamber 111|: is kept by itself, so that as the new charge is sucked inte the rear end of the cylinder the said rear end contains a larger proportion of the new charge than dees chamber 1111 of the piston. As the piston begins te return on the back stroke admission-valve G2 and ex IOC haustvalve 64 are closed, and admissionvalve 63 is opened by means of cam 74, valve 84 at the forward end of chamber 39 being opened at the same time by means of pin 93 andlever 89. The continued backward movement of the piston causes the gases in the rear end of the cylinder to be compressed and a new charge to be sucked into the forward end thereof through opening 59, chamber 53, opening 58, chamber 54, and port 44. As the gas is compressed in the rear end of the cylinder aportion of the mixed gas which is in the said rear end passes through opening 116 of plate 115 and mixes with the dead gas in chamber 114, but there still remains in the cylinder a greater proportion of the new charge than is in chamber 114. It is therefore much easier to vcause an explosion than it would be if all of the new charge were mixed with all of the dead gas. As the piston reaches the end of its back stroke contact 122 comes into engagement with contact 112 and spring 111 is slightly flexed, as shown in Fig. 2, so as to insure a good contact. At the same time gear 99 has been rotated by shaft 69 until pin 123 has been brought into contact with plate 126, and as valve 63 is closed and the piston moves forward the said contacts 122 and 112 are separated, a spark is formed and an explosion occurs, and the various operations are continued in the order described. As the speed increases the balls of the governor cause arm 97 to be raised and thereby rock shaft 95. The movement of said shaft causes arm 94 to press down upon the inner end of lever 89 and thereby cause the outer end thereof to be raised. @wing to spurs 91 on lever 89 and the notched end 92 of pin 93 said pin will continue to engage with lever 89 until the speed of the engine increases so much as to cause the said lever to be lifted entirely out of the path of movement of the pin. When this occurs, the admission-valve will continue to operate, but the pin 93 carried thereby will fail to open valve 84, so that no new charge will be introduced into that end of the cylinder and an explosion will be skipped. It will be noticed that by constructing the holding means for springs 111 in the manner described each of said springs is entirely insulated from the cylinder, that the opening into the cylinder can be made perfectly tight, and that the said holding means may be bodily removed from the cylinder, so

tween said guides and falling to the bottom of the cylinder. It is therefore possible to renew the contact-points without dismantling the engine. By forming the piston, in the manner described any leakage which may occur past the packing-rings will pass into chamber 24 and from. there will be returned to the cylinder, so that there will be no loss from leakage past the piston, as is very common in the ordinary single; acting gas-engine. The air which is to be mixed with the gas is also heated in chamber 24 before said mixing occurs, and by this means a much more stable mixture is obtained and said mixture, being hot, is much more easily exploded than a mixture of cold air and gas.

I claim as my invention- 1. In a gas-engine, a piston so shaped as to form an air-chamber between a portion of said piston and the walls of the cylinder, the said air-chamber having no direct com munication with the combustion-chamber of the cylinder, an air-inlet leading into said chamber from the exterior of the cylinder, an air-outlet leading from said chamber, and intermediate valved connections between said air-outlet and the combustion-chamber of the cylinder, as and for the purpose set forth.

2. In a gas-engine, the combination with a cylinder, of a piston mounted therein and so shaped as to form an air-chamber, having no immediate connection with the interior of the cylinder, between the middle portion thereof and the cylinder, an air-inlet leading into said chamber from the exterior of the cylinder, an air-outlet leading from said chamber, a mixing-chamber adapted to receive the air from said outlet, a port leading into the cylinder near one end thereof, a valve-box secured to the cylinder over said port, the said valvebox being provided with a chamber which communicates with said port, an admissionchamber and an exhaust-chamber formed in said box and each communicating with said first-mentioned chamber, an admission-valve and an exhaust-valve mounted in saidbox, a communication formed between the mixingchamber and the admission-chamber, a gasinlet valve mounted in the mixing-chamber, means for operating the admission-valve and the exhaust-valve, means carried by the admission-valve for operating the gas -inlet valve, and means for exploding the gas in the cylinder, substantially as set forth.

3. In a gas-engine,the combination with the cylinder, of a piston mounted therein and so shaped as to form an air-chamber, having no immediate connection with the interior of the cylinder, between the middle portion thereof and the cylinder, an air-inlet leading into said chamber from the exterior of the cylinder, an air-outlet leading from said chamber into a mixing-chamber, a port leading into each end of the cylinder, a valve-box secured to the cylinder over each port, each of said IOO boxes being provided with a chamber which communicates with one of the ports and being also provided with an admission-chamber and an cxhaust-cha1nber,an admission-valve and an exhaust-valve mounted in each valve-box and leading from their respective chambers to the first-mentioned chamber, a gas-inlet valve mounted in the mixing-chamber near each end thereof a passage formingareommui nication between each admission-chamber and the mixing-chamber, means for operating the admission and exhaust valves, means earried by each admission-valve for operating one of the gas-inlet valves, and means for causing an explosion in each end of the cylinder.

fi. ln a gas-en gine, a piston therefor having formed in the end thereof a chamber, a plate secured to the end of said piston but partially closing the open end of said chamber, as and for the purpose set forth.

5. In an engine, the combination with a doubleended cylinder and an exhaust-valve mounted at each end thereof, of two pipes leading one from each of said exhaust-valves and joined together at an acute angle to each other, as and for the purpose set forth.

G. In an engine, the combination with a double-ended cylinder and an exhaust-valve mounted at each end thereof, of an exhaustdrum, two pipes leading one from each of said exhaust-valves and j oined together at an acute angle to each other by means of a coupling which leads into the exhaust-drum, as and for the purpose set forth.

7. ln a gas-engine, the combination with a cylinder having a uniform bore, of a piston mounted therein, a port opening into the cylinder near each end thereof, a pair of valveboxes secured to the cylinder, one over each port, each of said boxes being provided with a chamber which communicates with one of the ports, and being also provided with an admission-chamber and an exhaust-eha1nber, each of said chambers being connected with the iirst-nientioned chamber and the openings therebetween being' closed by suitable admis sion and exhaust valves, a mixing-chamber mounted between and connecting the admissionschambers of both valve-boxes, a gas-in let valve mounted near each end of the mixing-chamber, a lever pivoted near the stem of each valve and each having one of its ends in connection with one of said valve-stems, a shaft mounted in suitable bearings on the engine-frame, a series of cams carried by said shaft, one of each of said cams being adapted to engage the opposite end of one of each of the levers, a lever carried by each of the gasinlet valves and projecting through the easing of the mixing-chamber, a pin carried by each of the admission-valves and each adapted to engage the end of one of said levers, and means for exploding the gas in cach end of the cylinder, all substantially as set forth.

8. in a gas-engine, the combination with a cylinder, of a piston mounted therein, a port openinginto the cylinder near each end thereof, a pair of valve-boxes secured to the eylinder one over each port, each of said boxes being provided with a chamber which eoinmunieates with one of the ports, and being also provided with an admission-chamber and an exhaust-chamber, each of said chambers being connected with the first mentioned chamber, and the openings therebetween being closed by suitable admission and exhaust valves, a mixing-chamber mounted between and connecting the admission-chambers of )oth valve-boxes, a gas-inlet valve mounted near each end of the mixing-chamber, a lever pivoted near the stem of each admission and exhaust valve and each having one of its ends in connection with one of said valvestems, a shaft mounted in suitable bearings on the engine-frame, a series of cams carried by said shaft, one of each of said cams being adapted to engage the opposite end oi' one of each of the levers, a lever carried by each of the gas-inlet valves and projecting through the easing of the mixing-chamber, a pin carried by each of the ad mission-valves and each adapted to engage the end of one of said levers, a pair of contact-pieces each insulated from the piston and extending one into each end of the cylinder, means for connecting each of said contacts with one pole of a suitable bat tery, a pair of eontaet-pieces secured to the piston and carried thereby, the said second pair of contacts being adapted to be brought alternately into engagement with the iirst pair of contacts by the movement of the piston, a pair of contact-pieces carried by the before-mentioned shaft, a contact-piece pro jecting into the path of said last-mentioned cont-acts and adapted to be engaged thereby, and means for connecting said last-mentioned contact with the opposite pole of a battery, all combined and arranged to cooperate substantially as and for the purpose set forth.

9. In a gas-engine, the combina-tion with the piston, of an arm projecting from the end thereof, a standard carried by said arm and longitudinally adjustable thereon, the said standard forming one of the terminals of an electric circuit.

10. In a gas-engine, the combination with the piston, of a pair of parallel guides projecting from the end thereof the opposed edges of said guides being opposi tely beveled, a nut adapted to slide between and supported by said beveled edges, a screw threaded standard adapted to engage said nut, and a collar carried by said standard and arranged to engage said guides in opposition to said nut, whereby, the standard may be adjust ably secured in position along said guides.

ll. ln a gas-engine, the combination with a cylinder-head and a piston-rod extending therethrough, ot' a hollow shield projecting from the inner end of said head into the eylinder and surrounding the piston-rod but out IOO of Contact therewith and forming no part of the bearing,` thereof, substantially as and for the purpose set forth.

l2. In a gas-engine, the combination With a Cylinder having the middle portion thereof of smaller diameter than the ends thereof, of an oil-bridge carried by said piston and eX- tending from end to end thereof and provided in its upper surface With a groove extending longitudinally thereof, and means for intro- 1o dueing oil into said groove, substantially as set forth.

Y FRED W. SPACKE. Witnesses:

A. M. Hoon, M. V. Hoon. 

